Changing course has doomed more PMs than it has revived

Gordon Brown's hopes of reviving his political fortunes with a series of bold policy strokes to impress voters find some echoes in election history, but more of them point to looming defeat than a reversal of fortunes.

In recent memory, the conspicuous policy switch which helped win a new mandate for an embattled government came after 1990, when John Major succeeded the ousted Margaret Thatcher and reversed her flagship policy for local government finance, the poll tax, which had triggered riots. Major imposed a banded property tax which survives as the council tax, and won the 1992 election against predictions.

But there were other switches. Norman Lamont's pre-election budget that year also crucially wrongfooted Labour by introducing a 20p lower tax rate, underlining mistrust in Neil Kinnock's tax-and-spend policies.

More recently, Tony Blair was persuaded by his then foreign secretary, Jack Straw, a closet Eurosceptic, to promise a referendum on the prospective EU constitution ahead of the 2005 election, in order to head off Michael Howard's challenge. Though French and Dutch "Nos" torpedoed the constitution, the pledge still haunts Labour as the Lisbon treaty struggles for acceptance. Threatened by his Ukip-voting flank, David Cameron is still committed to a referendum.

What may worry Brown in 2009 are memories of half-baked schemes from Major's ministers – including hasty pension reform plans – which backfired in 1996-97, reinforcing an air of incompetence.

All governments trim unpopular policies as polling day looms, though opposition parties are much more often forced to reverse their own hostility to those of incumbent governments which have proved successful with the voters.

After a series of election defeats by Thatcher in 1979-87, Labour was forced to abandon its long-standing hostility to basic policies such as nuclear weapons, EU membership and even council house sales. Since 1997, the Tories have been forced to embrace the national minimum wage and a tax-funded NHS, popular Labour policies which they previously opposed.

In 1982 Thatcher gave in to the miners because she had seen them twice defeat Ted Heath's government in the 70s and was not ready for a showdown so close to the 1983 election. After she had won it (thanks to her reconquest of the Falklands) she took them on.

The worst pre-election miscalculation of modern times was Stanley Baldwin's. In the depression of 1923 as a new prime minister he wanted to impose protectionist tariffs to help British industry and felt obliged to fulfil his predecessor's pledge to hold an election first. Baldwin lost his majority and Labour's first minority government was the result.